Occasionally some users experience activation issues in Microsoft Office 365 for Windows, and their Office applications will report that they are not licensed. This is practically always caused by issues on the local device, rather than an account not being licensed for Office. This article describes a few common resolutions to those issues.
Sign out / Sign in
The first step to try is to sign out from Office then sign back in. This can be done by following Microsoft's instructions at the following links:
Sign out: https://support.microsoft.com/en-us/office/sign-out-of-office-5a20dc11-47e9-4b6f-945d-478cb6d92071
Sign in: https://support.microsoft.com/en-us/office/sign-in-to-office-b9582171-fd1f-4284-9846-bdd72bb28426
Microsoft Support and Recovery Assistant
If signing out and signing back in did not fix the problem. Please run the Office Activation solution in Microsoft's Support and Recovery Assistant tool. It can detect and automatically fix many issues with activation, and can be downloaded from https://aka.ms/SARA-OfficeActivation-OF.
Other Troubleshooting Steps
If neither of the previous solutions resolved the issue, please refer to Microsoft's troubleshooting guide at https://support.microsoft.com/en-us/office/unlicensed-product-and-activation-errors-in-office-0d23d3c0-c19c-4b2f-9845-5344fedc4380?WT.mc_id=365AdminCSH_Smc